Field of the Invention
The invention relates to a remotely controllable clamping and tensioning or tautening device on a printing-unit cylinder, which may be provided in a printing unit of a rotary printing machine.
The published European Patent Application EP 0 737 574 A2 relates to a tensioning device in a rotary printing machine. In this device for fastening and tensioning a rubber blanket, a printing blanket or a printing plate on a cylinder of a rotary printing machine, the objective is to provide a tensioning or tautening of the printing blanket that is uniform over the entire web width as a result of torsion-free rotation of a tensioning spindle. In this regard, a uniform retensioning should also be able to take place during operation. In accordance therewith, the tensioning spindle is provided with toothing on the circumference thereof, and the toothing meshes with racks which are arranged so as to be movable transversely to the axis of rotation of the tensioning spindle. The racks are arranged so as to be drivable by an actuator counter to a prestressing force of springs.
The published German Patent Application DE 37 22 174 C2 is concerned with a device for clamping a flexible printing plate on the plate cylinder of a sheet-fed rotary printing machine. In this device for clamping a flexible printing plate on the plate cylinder of a sheet-fed rotary printing machine, one end of the printing plate that is formed with a bend can be placed onto the edge of the plate cylinder, and the other end of the printing plate can be pressed against the one end of the printing plate by a tensioning bar. The tensioning bar is mounted so that it is swivellable coaxially with the axis of the plate cylinder, the tensioning bar being firmly seated on bearer rings which are loosely and laterally slid onto the two cylinder journals of the plate cylinder. The bearer rings are swivellable by an hydraulic tensioning device that, in a cavity formed in one of the cylinder journals, has a hydraulic cylinder equipped with an adjustable piston. The hydraulic cylinder is connected via a manifold or distributor system to ancillary cylinders which are arranged endwise in a recess formed in the plate cylinder, and each have an adjusting piston respectively resting in a force-locking manner against a crank pin mounted in the bearer rings eccentrically to the axis of the plate cylinder.
The published European Patent Document EP 0 534 579 B1 is concerned with a plate exchange device on a rotary printing machine. The plate exchange device includes a plate winding rod that is fitted swivellably in a winding-rod hole formed in an outer circumferential part of a plate cylinder and includes a spring groove extending virtually over the entire length of the latter. In addition, the plate exchange device includes a plurality of leaf springs, each formed from a leaf-spring element and having a U-shaped cross section, said leaf springs being provided in the spring groove and each having an end formed with a pressure part to load a leading end of a plate against a surface of a gap in the plate cylinder, and another end, formed with a curved part, to grip a curved end of the plate wound around a circumferential surface of the plate cylinder. In addition, provision is made for a preloaded element to preload the plate winding rod in a predetermined direction of rotation, and also for a plate winding-rod rotating unit, that is coupled by a cam mechanism to an end part of the plate winding rod. Further provided are a plate press roll extending in an axial direction of the plate cylinder and close to the circumferential surface thereof, and reciprocatingly driven towards and away from the leading end of the plate by a drive unit, as well as a control unit for actuating the plate winding rod, the plurality of leaf springs of the preloaded element, the plate winding-rod rotating unit and the plate press roll at previously determined times.
The published German Patent Document DE 39 36 458 C1 is concerned with a device for positionally-accurate rapid clamping and tensioning of printing plates. The invention relates to a device for positionally-accurate rapid clamping and tensioning of printing plates on a plate cylinder. Arranged in the frame walls are clamping tools which, following appropriate positioning of the plate cylinder, are insertable into coupling sleeves of the eccentric shafts of front and rear clamping rails, respectively, by having pressure medium applied thereto. The clamping and unclamping is then performed by rotating the clamping tools via levers and compressed-air cylinders. For the purpose of tensioning or tautening, a motor, such as a compressed-air motor, is arranged in the cylinder channel.